How many nucleons are present in an atom of Nobelium, N o 102 254 ? How many electrons are present in the atom? How many nucleons may be considered as neutrons?

Number of nucleons = Mass number Thus, number of nucleons = 254 Number of electrons = Number of protons = Atomic number Thus, number of electrons = 102 Now, number of neutrons = Mass number – Atomic number = 254 - 102 = 152

Complete the following table: Particle Atomic Number Mass Number Number of electrons Number of protons Number of neutrons Sodium atom 11 12 Aluminium ion 27 10 Chloride ion 18 18 Phosphorus atom 31 15 Cuprous iron 28 35

Atomic number = No.of electrons = No.of protons. Mass number = No.of protons + No.of neutrons. Using the above two formulae calculated the missing values in the table given in question. Particle Atomic Number Mass Number Number of electrons Number of protons Number of neutrons Sodium atom 11 23 11 11 12 Aluminium ion 13 27 10 13 14 Chloride ion 17 35 18 17 18 Phosphorus atom 15 31 15 15 16 Cuprous iron 29 64 28 29 35

Complete the following table: Name of the Particle Mass Number Atomic Number Protons Number of Electrons Neutrons Oxygen 8 8 Sodium ion 23 11 Bromine 35 45

For Oxygen, Atomic number = No.of electrons = No.of protons = 8 . Mass number = No.of protons + No.of neutrons = 8 + 8 = 16 . For Sodium ion, Atomic number = No.of electrons = No.of protons = 11 . No.of neutrons = Mass number - Atomic number = 23 - 11 = 12 . For Bromine, Atomic number = No. of protons = No.of electrons = 35 . Mass number = No.of protons + No.of neutrons = 35 + 45 = 80 . Name of the Particle Mass Number Atomic Number Protons Number of Electrons Neutrons Oxygen 16 8 8 8 8 Sodium ion 23 11 11 10 12 Bromine 80 35 35 35 45

Find the number of protons, electrons and neutrons in a A l 3 + 13 27 b O 2 - 8 15 .

a Number of protons = 13 . Number of neutrons = Mass number - Atomic number = 27 - 13 = 14 . As, aluminium has + 3 charge, Number of electrons = 13 - 3 = 10 . b Number of protons = 8 . Number of neutrons = Mass number - Atomic number = 15 - 8 = 7 . As, oxygen has - 2 charge, Number of electrons = 8 + 2 = 10 .

E M B I B E

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>PROBLEMS FOR PRACTICE

S C Kheterpal, S N Dhawan and, P N Kapil Solutions for Chapter: Structure of Atom, Exercise 1: PROBLEMS FOR PRACTICE

Author:S C Kheterpal, S N Dhawan & P N Kapil

S C Kheterpal Chemistry Solutions for Exercise - S C Kheterpal, S N Dhawan and, P N Kapil Solutions for Chapter: Structure of Atom, Exercise 1: PROBLEMS FOR PRACTICE

Attempt the practice questions on Chapter 2: Structure of Atom, Exercise 1: PROBLEMS FOR PRACTICE with hints and solutions to strengthen your understanding. Pradeep's Chemistry Vol 1 solutions are prepared by Experienced Embibe Experts.

Questions from S C Kheterpal, S N Dhawan and, P N Kapil Solutions for Chapter: Structure of Atom, Exercise 1: PROBLEMS FOR PRACTICE with Hints & Solutions

MEDIUM

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>PROBLEMS FOR PRACTICE>Q 1

Neutrons can be found in all atomic nuclei except in one case. Which is this atomic nucleus and what does it consist of?

EASY

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>PROBLEMS FOR PRACTICE>Q 2

How many nucleons are present in an atom of Nobelium, ${}_{102}^{254}{N o} ?$ How many electrons are present in the atom? How many nucleons may be considered as neutrons?

HARD

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>PROBLEMS FOR PRACTICE>Q 3

Complete the following table:

Particle	Atomic Number	Mass Number	Number of electrons	Number of protons	Number of neutrons
Sodium atom	$11$				$12$
Aluminium ion		$27$	$10$
Chloride ion			$18$		$18$
Phosphorus atom		$31$		$15$
Cuprous iron			$28$		$35$

HARD

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>PROBLEMS FOR PRACTICE>Q 4

Complete the following table:

Name of the Particle	Mass Number	Protons	Number of Electrons	Neutrons
Oxygen		$8$		$8$
Sodium ion	$23$	$11$
Bromine			$35$	$45$

EASY

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>PROBLEMS FOR PRACTICE>Q 5

Find the number of protons, electrons and neutrons in $(a) {}_{13}^{27}{A l^{3 +}} (b) {}_{8}^{15}{O^{2 -}} .$

MEDIUM

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>PROBLEMS FOR PRACTICE>Q 6

The elements $P (A t o m i c w e i g h t 39)$ and $Q (A t o m i c w e i g h t 80)$ contain $20$ and $45$ neutrons respectively in their nucleus. Give their electronic arrangements separately.

HARD

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>PROBLEMS FOR PRACTICE>Q 7

Give the name and atomic number of the inert gas atom in which the total number of $d$ -electrons is equal to the difference between the numbers of total $p$ and total $s$ electrons.

MEDIUM

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>PROBLEMS FOR PRACTICE>Q 8

A monoatomic anion of unit charge contains $45$ neutrons and $36$ electrons. Find the atomic number, mass number of the ion with its identification.